True Televisions have the CRT Tube !!
Welcome to the Obsolete Technology Tellye Web Museum. Here you will see a TV Museum showing many Old Tube Television sets
all with the CRT Tube, B/W ,color, Digital, and 100HZ Scan rate, Tubes technology. This is the opportunity on the WEB to see, one more time, what real technology WAS ! In the mean time watch some crappy lcd picture around shop centers (but don't buy them, or money lost, they're already broken when new) !!!

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and information about some of the electronic, electrical and electrotechnical technology relics that the Frank Sharp Private museum has accumulated over the years .

Premise: There are lots of vintage electrical and electronic items that have not survived well or even completely disappeared and forgotten.

Or are not being collected nowadays in proportion to their significance or prevalence in their heyday, this is bad and the main part of the death land. The heavy, ugly sarcophagus; models with few endearing qualities, devices that have some over-riding disadvantage to ownership such as heavy weight,toxicity or inflated value when dismantled, tend to be under-represented by all but the most comprehensive collections and museums. They get relegated to the bottom of the wants list, derided as 'more trouble than they are worth', or just forgotten entirely. As a result, I started to notice gaps in the current representation of the history of electronic and electrical technology to the interested member of the public.

Following this idea around a bit, convinced me that a collection of the peculiar alone could not hope to survive on its own merits, but a museum that gave equal display space to the popular and the unpopular, would bring things to the attention of the average person that he has previously passed by or been shielded from. It's a matter of culture. From this, the Obsolete Technology Tellye Web Museum concept developed and all my other things too. It's an open platform for all electrical Electronic TV technology to have its few, but NOT last, moments of fame in a working, hand-on environment. We'll never own Colossus or Faraday's first transformer, but I can show things that you can't see at the Science Museum, and let you play with things that the Smithsonian can't allow people to touch, because my remit is different.

There was a society once that was the polar opposite of our disposable, junk society. A whole nation was built on the idea of placing quality before quantity in all things. The goal was not “more and newer,” but “better and higher" .This attitude was reflected not only in the manufacturing of material goods, but also in the realms of art and architecture, as well as in the social fabric of everyday life. The goal was for each new cohort of children to stand on a higher level than the preceding cohort: they were to be healthier, stronger, more intelligent, and more vibrant in every way.

The society that prioritized human, social and material quality is a Winner. Truly, it is the high point of all Western civilization. Consequently, its defeat meant the defeat of civilization itself.

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

OLD, but ORIGINAL, Well made, Funny, Not remotely controlled............. and not Made in CHINA.

How to use the site:

- If you landed here via any Search Engine, you will get what you searched for and you can search more using the search this blog feature provided by Google. You can visit more posts scrolling the left blog archive of all posts of the month/year,or you can click on the main photo-page to start from the main page. Doing so it starts from the most recent post to the older post simple clicking on the Older Post button on the bottom of each page after reading , post after post.

You can even visit all posts, time to time, when reaching the bottom end of each page and click on the Older Post button.

- If you arrived here at the main page via bookmark you can visit all the site scrolling the left blog archive of all posts of the month/year pointing were you want , or more simple You can even visit all blog posts, from newer to older, clicking at the end of each bottom page on the Older Post button.So you can see all the blog/site content surfing all pages in it.

- The search this blog feature provided by Google is a real search engine. If you're pointing particular things it will search IT for you; or you can place a brand name in the search query at your choice and visit all results page by page. It's useful since the content of the site is very large.

Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

Every CRT Television saved let revive knowledge, thoughts, moments of the past life which will never return again.........

Many contemporary "televisions" (more correctly named as displays) would not have this level of staying power, many would ware out or require major services within just five years or less and of course, there is that perennial bug bear of planned obsolescence where components are deliberately designed to fail and, or manufactured with limited edition specificities..... and without considering........picture......sound........quality........

GENERAL DESCRIPTIONHaving the capability to demodulate IF signals with eitherpositive or negative-going video information, theTDA4504B (Fig.1) is contained within a 32 pinencapsulation. It includes a three-stage vision IF amplifier,mute circuit, AFC and AGC circuitry, fully synchronisedhorizontal and vertical timebases with drive circuits andintegral three-level sandcastle pulse generator.A functional colour tv receiver can thus be realized with theaddition of a tuner, audio demodulator and amplifier,chroma decoder and respective line and field deflectioncircuitry.

FUNCTIONAL DESCRIPTIONVision IF amplifier, demodulatorand video amplifierEach of the three AC-coupled IFstages permit the omission of DCfeedback and possess a controlrange in excess of 20 dB.The IF amplifier, which is completelysymmetrical, is followed by a passivesynchronous demodulator providing aregenerated carrier signal. This islimited by a logarithmic limiter circuitprior to its application to thedemodulator.A noise clamp circuit is provided atthe video input (pin 16) to limitinterference pulses below the sync tiplevel and is more efficient than anoise inverter in providing improvedpicture stability during the presence ofinterference.The video amplifier has good linearityand bandwidth figures.AFC-circuitObtaining the AFC reference signalfrom the demodulator tuned circuitpresents the advantage of utilizing asingle tuned circuit and oneadjustment. However, since thefrequency spectrum of the signalapplied to the demodulator isdetermined by the characteristic ofthe SAW filter, the resultantasymmetrical spectrum with respectto the vision carrier causes the AFCoutput voltage to be dependent uponthe video signal. The TDA4504B thuscontains a sample-and-hold circuit.With negative-going vision signals theAFC is active only during the syncpulse period. When positive-goingsignals are applied to the device,however, the AFC is continuouslyactive but filtered to ensure only asmall by-pass current is present in thesample-and-hold circuit.With weak input signals the drivesignal will contain considerable noisewhich also possesses anasymmetrical frequency spectrumand could create an offset in the AFCoutput voltage. The inclusion of anotch in the demodulator tuned circuitminimises this effect.The sample-and-hold circuit isfollowed by a high impedance outputamplifier. Thus the AFC controlgradient depends upon the loadimpedance.The AFC polarity switch is combinedwith the start circuit (pin 12). It has anegative slope when pin 12 is open orconnected to the main supply and apositive slope when pin 12 isgrounded. The AFC is disabled whenthe sample connection (pin 22) isgrounded.

AGC circuitFor signals employing negative modulation the AGC detector operates on peak sync level but upon peak white contentwith those having positive modulation. Selection is facilitated by the system switch (pin 32):The AGC detector currents are:With a 6.8 mF AGC capacitor, the video tilt will be < 10% for positively modulated signals and < 2% for negativemodulation.To obtain a rapid AGC action when executing a search tuning operation with the circuit set for peak white AGC, thecharge current is held at 55 mA until the detection of a transmitted signal.The transmitter identificationA mute signal is generated to disable the audio preamplifier of an audio demodulator during the absence of atransmission signal. When the video switch is in the internal mode, the identification of a transmitted signal is derivedfrom the coincidence detector.In the external mode the IF part of the circuit has its own identification system. The system relies upon the detection ofsync. pulses on the incoming IF signal. The separated horizontal sync pulse charges the capacitor on pin 25 which drivesthe mute output (pin 14).The connection of a 1 MW resistor between pin 25 and VCC results in the mute information being overruled by the50/60 Hz information derived from the internal vertical divider section.

50/60 Hz InformationIn the external video mode and with a resistor of 1 MW from pin 25 to VCC the mute is overruled by the 50/60 Hzinformation from the divider system.

VCR switchFlywheel horizontal synchronization is desirable when receiving weak signals marred by noise but is usually unnecessarywhen receiving stronger off-air signals unless certain types of interference or multipath reception are apparent. Due tothe inherent instability of VCR signals, however, the horizontal time constant should be shorter to prevent loss ofhorizontal synchronization in the early part of the scan. Provision is therefore incorporated to automatically switch theshort time constant such that a strong signal instigates the 'VCR' mode and a weak signal triggers the 'TV' mode.The connection of a switch to pin 17 provides for this to be accomplished manually and may take the form of an auxiliaryswitching function associated with a designated program selector button.The TDA4504B has a separate pin (pin 17) for the VCR switch:Video-switchVideo output from the demodulator is filtered to remove the audio carrier and DC-coupled to pin 16. If AC-coupling isemployed the internal noise clamp will operate on sync. tips.The TDA4504B provides the opportunity for a direct video connection (e.g. via a peritel connector) to be made to thedevice at pin 13. Selection between internal and external video is made by applying a switching potential to pin 18.Video switch:Gain reductionTo prevent crosstalk between the IF stages and the horizontal oscillator when the device is operated in its external videomode with no RF input, the TDA4504B incorporates an option to reduce IF gain by 20 dB. This is accomplished byconnecting a 39 kW resistor between pin 17 and ground. Omission of this component results in the IF amplifier remainingat full gain.In the internal video mode the resistor must be disconnected to achieve the auto-VCR mode.Input Signal50 Hz 60 Hz None Don’t care Don’t care Don’t carePin 9/10Pin 25 9.5 9.5 0.3 9.5 9.5 9.5Pin 28 50 Hz 60 Hz None 50 Hz 60 Hz NonePin 18 LOW LOW LOW HIGH HIGH HIGHPin 14 12 9 0.3 12 9 12pin 17 HIGH: VCR mode fast time constant; ungatedpin 17 n.c.: auto VCR modepin 17 LOW: TV mode slow time constant; gatedpin 18 LOW: internal videopin 18 HIGH: external video

Horizontal synchronizationThe horizontal synchronization circuitof the TDA4504B has been designedas follows:· The retrace of the horizontaloscillator occurs during thehorizontal retrace and not duringthe scan period. This has theadvantage that no interference willbe visible on the screen whenreceiving weak input signals. Videocrosstalk will not disturb the phaseof the horizontal locking.· Reduced frequency shift of thehorizontal oscillator due to noisesince the horizontal phase detectorreference signal is moresymmetrical and independent ofthe supply voltage andtemperature.· The phase detector current ratio forstrong and weak signals isincreased to obtain a betterperformance during both VCRplayback and weak signalreception. The switching level isalso independent of temperatureand supply voltage.Vertical synchronizationGeneration of the vertical sawtooth(pin 3) is accomplished by a dividerthat permits the production of avertical frequency of either 50 Hz or60 Hz with freedom from adjustment,amplitude correction and maximuminterference/disturbance protection.A discriminator window checks thevertical trigger pulse. When thetrigger pulse occurs before count 576,the divider system operates in the60 Hz mode otherwise the 50 Hzmode is selected. (2 clock pulsesequal one horizontal line).The divider section operates withdifferent reset windows. Thesewindows are activated via an up/downcounter. This increases its count by 1for each occasion the separatedvertical sync pulse is within theselected window. On each occasionthe vertical sync. pulse is not withinthe selected window, the count isreduced by 1.LARGE (SEARCH) WINDOW; DIVIDERRATIO BETWEEN 488 - 722This mode is valid for the followingconditions:1 divider locking to anothertransmitter2 divider ratio found, not withinthe narrow window limits3 up/down counter value of thedivider system operating innarrow window mode, countfalls below 10.NARROW WINDOW; DIVIDER RATIOBETWEEN 522 - 528 (60 HZ) OR 622 -628 (50 HZ)The divider switches to this modewhen the up/down counter hasreached its maximum value of 15approved vertical sync pulses. Whenthe divider operates in this mode anda vertical sync pulse is missing withinthe window, the divider is reset at theend of the window and the countlowered by 1. At a counter valuebelow 10, the divider switches to thelarge window mode.An anti-top flutter pulse is alsogenerated by the divider system. Thisinhibits the horizontal phase-1detector during the vertical syncpulse. The width of this pulsedepends upon the divider mode. Forthe large window mode the start isgenerated at the divider reset. In thenarrow window mode the anti-topflutter pulse starts at the beginning ofthe first equalizing pulse. The anti-topflutter pulse ends at count 10 for 50Hz and count 12 for 60 Hz.When out-of-sync is detected by thecoincidence detector, the divider isswitched to count 625. This results ina stable vertical amplitude when noinput signal is available.

TDA3827 TV-sound demodulator circuit with SCART switches and AF control

TDA3505 Video control combination circuit with automatic cut-off control

GENERAL DESCRIPTION
The TDA3505 and TDA3506 are monolithic integrated circuits which perform video control functions in a PAL/SECAM
decoder. The TDA3505 is for negative colour difference signals -(R-Y), -(B-Y) and the TDA3506 is for positive colour
difference signals +(R-Y), +(B-Y).
The required input signals are: luminance and colour difference (negative or positive) and a 3-level sandcastle pulse for
control purposes. Linear RGB signals can be inserted from an external source. RGB output signals are available fordriving the video output stages. The circuits provide automatic cut-off control of the picture tube.
Features
· Capacitive coupling of the colour difference and
luminance input signals with black level clamping in the
input stages
· Linear saturation control acting on the colour difference
signals
· (G-Y) and RGB matrix
· Linear transmission of inserted signals
· Equal black levels for inserted and matrixed signals
· 3 identical channels for the RGB signals
· Linear contrast and brightness controls, operating on
both the inserted and matrixed RGB signals
· Peak beam current limiting input
· Clamping, horizontal and vertical blanking of the three
input signals controlled by a 3-level sandcastle pulse
· 3 DC gain controls for the RGB output signals (white
point adjustment)
· Emitter-follower outputs for driving the RGB output
stages
· Input for automatic cut-off control with compensation for
leakage current of the picture tube

Notes
1. < 110 mA after warm-up.
2. Values are proportional to the supply voltage.
3. When V11-24 < 0,4 V during clamping time - the black levels of the inserted RGB signals are clamped on the black
levels of the internal RGB signals.
When V11-24 > 0,9 V during clamping time - the black levels of the inserted RGB signals are clamped on an internal
DC voltage (correct clamping of the external RGB signals is possible only when they are synchronous with the
sandcastle pulse).
4. When pins 21, 22 and 23 are not connected, an internal bias voltage of 5,5 V is supplied.
5. Automatic cut-off control measurement occurs in the following lines after start of the vertical blanking pulse:
line 20: measurement of leakage current (R + G + B)
line 21: measurement of red cut-off current
line 22: measurement of green cut-off current
line 23: measurement of blue cut-off current
6. Black level of the measured channel is nominal; the other two channels are blanked to ultra-black.
7. All three channels blanked to ultra-black.
The cut-off control cycle occurs when the vertical blanking part of the sandcastle pulse contains more than 3 line
pulses.
The internal blanking continues until the end of the last measured line.
The vertical blanking pulse is not allowed to contain more than 34 line pulses, otherwise another control cycle begins.
8. The sandcastle pulse is compared with three internal thresholds (proportional to VP) and the given levels separate
the various pulses.
9. Blanked to ultra-black (-25%).
10. Pulse duration ³ 3,5 ms.

A coil bobbin for a fly-back transformer or the like having a bobbin proper. A plurality of partition members or flanges are formed on the bobbin proper with a slot between adjacent ones. At least first and second coil units are formed in the bobbin proper, each having several slots, formed between the flanges, and first and second high voltage coils are wound on the first and second coil units in opposite directions, respectively. A rectifying means is connected in series to the first and second coil units, and a cut-off portion or recess is provided on each of the partition members. In this case, a wire lead of the coil units passes from one slot to an adjacent slot through the cut-off portion which is formed as a delta groove, and one side of the delta groove is corresponded to the tangent direction to the winding direction.

1. A fly-back transformer comprising a coil bobbin comprising a plurality of parallel spaced discs with a first adjacent plurality of said disc formed with delta shaped slots having first edges which extend tangentially to a first winding direction and a first winding wound on said first adjacent plurality of said discs in said first winding direction, a second adjacent plurality of said discs formed with delta shaped slots having first edges which extend tangentially to a second winding direction opposite said first winding direction and a second winding wound on said second adjacent plurality of said discs in said second winding direction, a third adjacent plurality of said discs formed with delta shaped slots having first edges which extend tangentially to said first winding direction and a third winding wound on said third adjacent plurality of said discs in said first winding direction and said second plurality of adjacent discs mounted between said first and third plurality of adjacent discs. 2. A fly-back transformer according to claim 1 wherein adjacent ones of said first adjacent plurality of discs are mounted such that their delta shaped slots are orientated 180 degrees relative to each other. 3. A fly-back transformer according to claim 2 including a first winding turning partition mounted between said first and second adjacent plurality of discs and formed with grooves and notches for changing winding direction between said first and second windings and a second winding turning partition mounted between said second and third adjacent plurality of discs and formed with grooves and notches for changing the winding direction between said second and third windings. 4. A fly-back transformer according to claim 3 wherein said first and second winding turning partitions are formed with winding guiding slots for guiding the winding between the first, second and third adjacent plurality of discs. 5. A fly-back transformer according to claim 2 including a first rectifying means connected between one end of said first winding and one end of said second winding, and a second rectifying means connected between the second end of said second winding and one end of said third winding. 6. A fly-back transformer according to claim 5 wherein the second end of said first winding is grounded and a third rectifying means connected between the second end of said third winding and an output terminal.

Description:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a bobbin structure for high voltage transformers, and is directed more particularly to a bobbin structure for high voltage transformer suitable for automatically winding coils thereon.
2. Description of the Prior Art
In the art, when a wire lead is reversely wound on a bobbin separately at every winding block, a boss is provided at every winding block and the wire lead is wound on one block, then one end of the wire lead is tied to the boss where it will be cut off. The end of the wire lead is tied to another boss, and then the wire lead is wound in the opposite direction. Therefore, the prior art winding method requires complicated procedures and the winding of the wire lead cannot be rapidly done and also the winding can not be performed automatically. Further, the goods made by the prior art method are rather unsatisfactory and have a low yield.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly an object of the invention is to provide a coil bobbin for a fly-back transformer or the like by which a wire lead can be automatically wound on winding blocks of the coil bobbin even though the winding direction is different among the different winding blocks.
Another object of the invention is to provide a coil bobbin for a fly-back transformer or the like in which a bridge member and an inverse engaging device for transferring a wire lead from one wiring block to an adjacent wiring block of the coil bobbin and wiring the wire lead in opposite wiring directions between adjacent wiring blocks, and a guide member for positively guiding the wire lead are provided.
According to an aspect of the present invention, a coil bobbin for a fly-back transformer or the like is provided which comprises a plurality of partition members forming a plurality of slots, a first coil unit having several slots on which a first high voltage coil is wound in one winding direction, a second coil unit having several slots on which a second high voltage coil is wound in the other direction, a rectifying means connected in series to the first and second coil units, and a cut-off portion provided on each of the partition members, a wire lead passing from one slot to an adjacent slot through the cut-off portions, each of the cut-off portions being formed as a delta groove, and one side of the delta groove corresponding to a tangent to the winding direction.
The other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings through which the like reference numerals and letters designate the same elements and parts, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the construction of a fly-back transformer;
FIG. 2 is a connection diagram showing an example of the electrical connection of the fly-back transformer shown in FIG. 1;
FIG. 3 is a schematic diagram showing an example of a device for automatically winding a wire lead of the fly-back transformer on its bobbin;
FIG. 4 is a perspective view showing an example of the coil bobbin according to the present invention;
FIG. 5 is a plan view of FIG. 4;
FIGS. 6 and 7 are views used for explaining recesses or cut-off portions shown in FIGS. 4 and 5; and FIGS. 8A and 8B cross-sectional views showing an example of the inverse engaging means according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
When the high voltage winding of a fly-back transformer used in a high voltage generating circuit of a television receiver is divided into plural ones and then wound on a bobbin, the divided windings (divided coils) are connected in series through a plurality of rectifying diodes.
When the winding is divided into, for example, three portions, such as divided coils La, Lb and Lc, they are wound on a bobbin proper 1 from, for example, left to right sequentially in this order as shown in FIG. 1. In this case, if the divided coils La and Lc are selected to have the same sense of turn and the middle coil Lb is selected to have the opposite sense of turn from the coils La and Lc, the distance between the terminal end of coil La and the start of coil Lb and the distance between the terminal end of coil Lb and the start of coil Lc can be got relatively long. Therefore, diodes Da and Db can be mounted by utilizing the space above the block on which the middle coil Lb is wound as shown in FIG. 1, so that it becomes useless to provide spaces for diodes between the divided coils La and Lb and between the divided coils Lb and Lc and hence the bobbin proper 1 can be made compact.
FIG. 2 is a connection diagram showing the connection of the above fly-back transformer. In FIG. 2, reference numeral 2 designates a primary winding (Primary coil) of the fly-back transformer, reference letter L designates its high voltage winding (secondary coil), including divided coils La, Lb and Lc, 3 an output terminal, and 4 a lead wire connected to the anode terminal of a cathode ray tube (not shown), respectively.
An example of the bobbin structure according to the invention, which is suitable to automatically wind coils, which are different in sense of turn in each winding block as shown in FIG. 1, on the bobbin, will be hereinafter described with reference to the drawings.
FIG. 3 is a diagram showing an automatic winding apparatus of a wire lead on a coil bobbin. If it is assumed that the wire lead is wound in the order of winding blocks A, B and C in FIG. 1 and the wire lead is wound on the block A with the bobbin proper 1 being rotated in the counter-clockwise direction as shown in FIG. 3, the relation between the bobbin proper 1 and the wire lead becomes as shown in FIG. 3. In this figure, reference numeral 6 designates a bobbin for feeding the wire lead.
Turning to FIG. 4, an example 10 of the bobbin structure or coil bobbin according to the present invention will be described now. In this example, the winding blocks A, B and C for the divided coils La, Lb and Lc are respectively divided into plural slots or sections by plural partition members or flanges 11, and a cut-off portion or recess 12 is formed on each of the flanges 11 through which the wire lead in one section is transferred to the following winding section.
As shown in FIG. 6, each recess 12 is so formed that its one side extends in the direction substantially coincident with the tangent to the circle of the bobbin proper 1 and its direction is selected in response to the sense of turn of the winding or wire lead. In this case, the direction of recess 12 means the direction of the opening of recess 12, and the direction of recess 12 is selected opposite to the sense of turn of the winding in the present invention.
Now, recesses 12A, which are formed in the winding block A, will be now described by way of example. The positions of recesses 12A formed on an even flange 11Ae and an odd flange 11A 0 are different, for example, about 180° as shown in FIGS. 6A and 6B. Since the bobbin proper 1 is rotated in the counter-clockwise direction in the winding block A and hence the sense of turn of the wire lead is in the clockwise direction, the recess 12A is formed on the even flange 11Ae at the position shown in FIG. 6A. That is, the direction of recess 12A is inclined with respect to the rotating direction of bobbin proper 1 as shown in FIG. 6A. In this case, one side 13a of recess 12A is coincident with the tangent to the circle of bobbin proper 1, while the other side 13b of recess 12A is selected to have an oblique angle with respect to the side 13a so that the recess 12A has a predetermined opening angle.
The opening angle of recess 12A is important but the angle between the side 13a of recess 12A and the tangent to the circle of bobbin proper 1 is also important in the invention. When the wire lead is bridged or transferred from one section to the following section through the recess 12A, the wire lead in one section advances to the following section in contact with the side 13a of recess 12A since the bobbin proper 1 is rotated. In the invention, if the side 13a of recess 12A is selected to be extended in the direction coincident with the tangent to the circle of bobbin proper 1, the wire lead can smoothly advance from one section to the next section without being bent.
In the invention, since the middle divided coil Lb is wound opposite to the divided coil La, a recess 12B provided on each of flanges 11B of the winding block B is formed to have an opening opposite to that of recess 12A formed in the winding block A as shown in FIGS. 6C and 6D.
As shown in FIG. 5, terminal attaching recesses 14 are provided between the winding blocks A and B to which diodes are attached respectively. In the illustrated example of FIG. 5, a flange 15AB is formed between the flanges 11A 0 and 11B 0 of winding blocks A and B, and the recesses 14 are formed between the flanges 11A 0 and 15AB and between 15AB and 11B 0 at predetermined positions. Then, terminal plates 16, shown in FIG. 4, are inserted into the recesses 14 and then fixed there to, respectively. The terminal plates 16 are not shown in FIG. 5. Between the winding blocks B and C and between the blocks A and B, similar terminal attaching recesses 14 are formed, and terminal plates 16 are also inserted thereinto and then fixed thereto.
As described above, since the divided coil Lb is wound opposite to the divided coils La and Lc, it is necessary that the winding direction of the wire lead be changed when the wire lead goes from the block A to block B and also from the block B to block C, respectively.
Turning to FIG. 7, an example of the winding or wire lead guide means according to the present invention will be now described. In FIG. 7, there are mainly shown a bridge member for the wire lead and an inverse member or means for the wire lead which are provided between the winding blocks A and B. At first, a bridge means 20 and its guide means 21, which form the bridge member, will be described. The bridge means 20 is provided by forming a cut-out portion or recess in the middle flange 15AB located between the winding blocks A and B. In close relation to the bridge means or recess 20, the guide means 21 is provided on a bridge section X A at the side of block A. This guide means 21 is formed as a guide piece which connects an edge portion 20a of recess 20 at the winding direction side to the flange 11A 0 of block A in the oblique direction along the winding direction through the section X A .
Next, an inverse engaging means 22 will be now described with reference to FIGS. 7 and 8. If the flange 11B 0 of FIG. 7 is viewed from the right side, the inverse engaging means 22 can be shown in FIG. 8A. In this case, the tip end of one side 13a of recess 12B 1 is formed as a projection which is extended outwards somewhat beyond the outer diameter of flange 11B 0 . The inverse engaging means 22 may take any configuration but it is necessary that when the rotating direction of the bobbin proper 1 is changed to the clockwise direction, the wire lead can be engaged with the recess 12B 1 or projection of one side 13a and then suitably transferred to the next station.
Another guide means 23 is provided on a bridge section X B at the side of winding block B in close relation to the inverse engaging means 22. The guide means 23 is formed as a guide surface which is a projected surface from the bottom surface of section X B and extended obliquely in the winding direction. This guide means or guide surface 23 is inclinded low into the means 22 and has an edge 23a which is continuously formed between the middle flange 15AB and the flange 11B 0 .
In this case, it is possible that the guide means 21 and guide surface 23 are formed to be the same in construction. That is, both the guide means 21 and 23 can be made of either the guide piece, which crosses the winding section or guide surface projected upwards from the bottom surface of the winding section. It is sufficient if the guide means 21 and 23 are formed to smoothly transfer the wire lead from one section to the next section under the bobbin proper 1 being rotated.
Although not shown, in connection with the middle flange 15BC between the winding blocks B and C, there are provided similar bridge means 20, guide means 21, inverse engaging means 22 and another guide means 23, respectively. In this case, since the winding direction of the wire lead is reversed, the forming directions of the means are reverse but their construction is substantially the same as that of the former means. Therefore, their detailed description will be omitted.
According to the bobbin structure of the invention with the construction set forth above, the wire lead, which is transferred from the block A to the section X A by the rotation of bobbin proper 1, is wound on the section X B from the section X A after being guided by the guide piece 21 to the recess 20 provided on the middle flange 15AB, and then transferred to the recess 22 provided on the flange 11B 0 guide surface 23, bridged once to the first section of winding block B through the recess 22 (refer to dotted lines b in FIG. 7). Then, if the rotating direction of the bobbin proper 1 is reversed, the wire lead is engaged with the bottom of recess 22 (refer to solid lines b in FIG. 7). Thus, if the above reverse rotation of bobbin proper 1 is maintained, the wire lead is wound on the block B in the direction reverse to that of block A. When the wire lead is transferred from the block B to block C, the same effect as that above is achieved. Therefore, according to the present invention, the wire lead can be automatically and continuously wound on the bobbin proper 1.
After the single wire lead is continuously wound on blocks A, B and C of bobbin proper 1 as set forth above, the wire lead is cut at the substantially center of each of its bridging portions. Then, the cut ends of the wire lead are connected through diodes Da, Db and Dc at the terminal plates 16, respectively by solder.
In the present invention, the projection piece, which has the diameter greater than that of the flange 11B, is provided in the bridge recess 12 to form the inverse engaging means 22 as described above, so that when the winding direction is changed, the wire lead engages with the inverse engaging means 22 without errors when reversing the winding direction of the wire lead.
If the diameter of the projection piece of means 22 is selected, for example, to be the same as that of the flange 11B, it will not be certain that the wire lead engages with the means 22 because it depends upon the extra length of the wire lead and hence errors in winding cannot be positively avoided.
Further, in this invention, the bridge means is provided on the flange positioned at the bridging portion of the bobbin which has a number of dividing blocks separated by flanges, and the inverse engaging means is provided and also the guide means is provided at the former winding section to cooperate with the inverse engaging means. Therefore, the wire lead can be positively fed to the bridge means, and the transfer of the wire lead to the following winding section can be carried out smoothly.
Further, in this invention since one side of the recess 12 is selected coincident with the tangent of the outer circle of the bobbin proper 1 and also with the winding direction, the wire lead can be smoothly bridged to the following section. Due to the fact that the direction of recess 12 is changed in response to the winding direction, even if there is a block on which the wire lead is wound in the opposite direction to that of the other block, the wire lead can be continuously and automatically wound through the respective blocks.
The above description is given for the case where the present invention is applied to the coil bobbin for the high voltage winding of a fly-back transformer, but it will be clear that the present invention can be applied to other coil bobbins which require divided windings thereon with the same effects.
It will be apparent that many modifications and variations could be effected by one skilled in the art without departing from the spirits or scope of the novel concepts of the present invention, so that the spirits or scope of the invention should be determined by the appended claims only.

No comments:

Post a Comment

The most important thing to remember about the Comment Rules is this: The determination of whether any comment is in compliance is at the sole discretion of this blog’s owner.

Comments on this blog may be blocked or deleted at any time.Fair people are getting fair reply. Spam and useless crap and filthy comments / scrapers / observations goes all directly to My Private HELL without even appearing in public !!!

The fact that a comment is permitted in no way constitutes an endorsement of any view expressed, fact alleged, or link provided in that comment by the administrator of this site.This means that there may be a delay between the submission and the eventual appearance of your comment.

Requiring blog comments to obey well-defined rules does not infringe on the free speech of commenters.

Resisting the tide of post-modernity may be difficult, but I will attempt it anyway.

Your choice.........Live or DIE.That indeed is where your liberty lies.

IMPORTANT NOTE: - FRANK SHARP obsoletetellyemuseum.blogspot.comwas founded as a public free WEB Museum to all kind of people and amateur and professional CRT TELEVISION Lovers who enjoy using and/or preserving - restoring vintage CRT Televisions sets, or only curious public who was unaware of that kind of technolgy of the past. The purpose is to provide information about vintage Television Receivers Publicy on the WEB that is generally difficult to locate; all this as a important milestone general worldwide reference for the future, globally in the public interest.obsoletetellyemuseum.blogspot.com does not provide support or parts for any apparatus on this site nor do we represent any manufacturer listed on this site in any way. Catalogs, manuals and any other literature that is available on this site is made available for a historical record only. Please remember that safety standards have changed over the years and information in old manuals as well as the old Television receivers themselves may not meet modern standards. It is up to the individual user to use good judgment and to safely operate old machinery. The obsoletetellyemuseum.blogspot.com web site will assume NO responsibilities for damages or injuries resulting from information obtained from this site. No offer to sell or license — Nothing in this site/Blog may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights.

Many topics are permanent, so may be updated to any material, for add or correct info.

Sure Fun Times, A working TV Discovered with a CRT Oscilloscope !

Safety Hazards:

------------------------------------------------------Safety Hazards in Radio and TV Repair,------------------------------------------------------

People who believe they can conquer nature are clueless that the laws of nature are a precondition of their existence. Their weapon is a miserable idea.When man attempts to rebel against the iron logic of Nature, he comes into struggle with the principles to which he himself owes his existence as a man. And this attack must lead to his own doom.

Anyone attempting to repair any electronic equipment who does not fully understand the shock hazards, as well as the fire hazards associated with working with electronic equipment, should not attempt such procedures! Improperly attempted repair can kill you and burn down your house.Devices that plug into the wall can produce a very lethal electric shock as well cause a fire from incorrect or careless repairs both during servicing or later on.Improper repair of battery operated devices can also result in bad consequences for you, the device, and any equipment attached to it.

Why some people do repairs themselved then? If you can do the repairs yourself, the equation changes dramatically asyour parts costs will be 1/2 to 1/4 of what a professional will chargeand of course your time is free. The educational aspects may also beappealing. You also will learn a lot in the process.

Consumer electronic equipment like TVs, computer monitors, microwave ovens, and electronic flash units, use voltages at power levels that are potentially lethal. Even more so for industrial equipment like lasers and anything else that is either connected to the power line, or uses or generates high voltage.

Normally, these devices are safely enclosed to prevent accidental contact. However, when troubleshooting, testing, making adjustments, and during repair procedures, the cabinet will likely be open and/or safety interlocks may be defeated. Home-built or modified equipment, despite all warnings and recommendations to the contrary - could exist in this state for extended periods of time - or indefinitely.

Depending on overall conditions and your general state of health, there is a wide variation of voltage, current, and total energy levels that can kill.

Microwave ovens in particular are probably THE most dangerous household appliance to service. There is high voltage - up to 5,000 V or more - at high current - more than an amp may be available momentarily. This is an instantly lethal combination.

TVs and monitors may have up to 35 kV on the CRTbut the current isn't low - like a wrong legend saying a "couple of milliamps" but relatively high because of the boost circuit technology and transformer design. However, the CRT capacitance can hold a painful charge for a long time. In addition, portions of the circuitry of TVs and monitors as well as all other devices that plug into the wall socket are line connected.This is actually even more dangerous than the high voltage due to the greater current available - and a few hundred volts can make you just as dead as 35 kV!

Electronic flash units and strobe lights, and pulsed lasers have large energy storage capacitors which alone can deliver a lethal charge - long after the power has been removed. This applies to some extent even to those little disposable pocket cameras with flash which look so innocent being powered from a single 1.5 V AA battery. Don't be fooled - they are designed without any bleeder so the flash can be ready for use without draining the battery!

Even some portions of apparently harmless devices like VCRs and CD players - or vacuum cleaners and toasters - can be hazardous (though the live parts may be insulated or protected - but don't count on it!

This information also applies when working on other high voltage or line connected devices like Tesla Coils, Jacobs Ladders, plasma spheres, gigawatt lasers, hot and cold fusion generators, cyclotrons and other particle accelerators, as well as other popular hobby type projects. :-)

In addition, read the relevant sections of the document for your particular equipment for additional electrical safety considerations as well as non-electrical hazards like microwave radiation or laser light. Only the most common types of equipment are discussed in the safety guidelines, below.

SAFETY guidelines:

These guidelines are to protect you from potentially deadly electrical shock hazards as well as the equipment from accidental damage.

Note that the danger to you is not only in your body providing a conducting path, particularly through your heart. Any involuntary muscle contractions caused by a shock, while perhaps harmless in themselves, may cause collateral damage. There are likely to be many sharp edges and points inside from various things like stamped sheet metal shields and and the cut ends of component leads on the solder side of printed wiring boards in this type of equipment. In addition, the reflex may result in contact with other electrically live parts and further unfortunate consequences.

The purpose of this set of guidelines is not to frighten you but rather to make you aware of the appropriate precautions. Repair of TVs, monitors, microwave ovens, and other consumer and industrial equipment can be both rewarding and economical. Just be sure that it is also safe!

Don't work alone - in the event of an emergency another person's presence may be essential.

Always keep one hand in your pocket when anywhere around a powered line-connected or high voltage system.

Wear rubber bottom shoes or sneakers. An insulated floor is better than metal or bare concrete but this may be outside of your control. A rubber mat should be an acceptable substitute but a carpet, not matter how thick, may not be a particularly good insulator.

Don't wear any jewelry or other articles that could accidentally contact circuitry and conduct current, or get caught in moving parts.

Set up your work area away from possible grounds that you may accidentally contact.

Have a fire extinguisher rated for electrical fires readily accessible in a location that won't get blocked should something burst into flames.

Use a dust mask when cleaning inside electronic equipment and appliances, particularly TVs, monitors, vacuum cleaners, and other dust collectors.

Know your equipment: TVs and monitors may use parts of the metal chassis as ground return yet the chassis may be electrically live with respect to the earth ground of the AC line. Microwave ovens use the chassis as ground return for the high voltage. In addition, do not assume that the chassis is a suitable ground for your test equipment!

If circuit boards need to be removed from their mountings, put insulating material between the boards and anything they may short to. Hold them in place with string or electrical tape. Prop them up with insulation sticks - plastic or wood.

If you need to probe, solder, or otherwise touch circuits with power off, discharge (across) large power supply filter capacitors with a 2 W or greater resistor of 100 to 500 ohms/V approximate value (e.g., for a 200 V capacitor, use a 20K to 100K ohm resistor). Monitor while discharging and/or verify that there is no residual charge with a suitable voltmeter. In a TV or monitor, if you are removing the high voltage connection to the CRT (to replace the flyback transformer for example) first discharge the CRT contact (under the insulating cup at the end of the fat red wire). Use a 1M to 10M ohm 1W or greater wattage resistor on the end of an insulating stick or the probe of a high voltage meter. Discharge to the metal frame which is connected to the outside of the CRT.

For TVs and monitors in particular, there is the additional danger of CRT implosion - take care not to bang the CRT envelope with your tools. An implosion will scatter shards of glass at high velocity in every direction. There is several tons of force attempting to crush the typical CRT. Always wear eye protection. While the actual chance of a violent implosion is relatively small, why take chances? (However, breaking the relatively fragile neck off the CRT WILL be embarrassing at the very least.)

Connect/disconnect any test leads with the equipment unpowered and unplugged. Use clip leads or solder temporary wires to reach cramped locations or difficult to access locations.

If you must probe live, put electrical tape over all but the last 1/16" of the test probes to avoid the possibility of an accidental short which could cause damage to various components. Clip the reference end of the meter or scope to the appropriate ground return so that you need to only probe with one hand.

Perform as many tests as possible with power off and the equipment unplugged. For example, the semiconductors in the power supply section of a TV or monitor can be tested for short circuits with an ohmmeter.

Provide a reliable means of warning that power is applied and that high voltage filter capacitor(s) still hold a charge during servicing. For example, solder a neon indicator lamp (e.g., an NE2 in series with a 100K ohm resistor) across the line input and a super high brightness LEDs in series with 100K, 1 W resistors across the main filter capacitor(s).

Use an isolation transformer if there is any chance of contacting line connected circuits. A Variac(tm) (variable autotransformer) is not an isolation transformer! However, the combination of a Variac and isolation transformer maintains the safety benefits and is a very versatile device. See the document "Repair Briefs, An Introduction", available at this site, for more details.

The use of a GFCI (Ground Fault Circuit Interrupter) protected outlet is a good idea but may not protect you from shock from many points in a line connected TV or monitor, or the high voltage side of a microwave oven, for example. (Note however, that, a GFCI may nuisance trip at power-on or at other random times due to leakage paths (like your scope probe ground) or the highly capacitive or inductive input characteristics of line powered equipment.) A GFCI is also a relatively complex active device which may not be designed for repeated tripping - you are depending on some action to be taken (and bad things happen if it doesn't!) - unlike the passive nature of an isolation transformer. A fuse or circuit breaker is too slow and insensitive to provide any protection for you or in many cases, your equipment. However, these devices may save your scope probe ground wire should you accidentally connect it to a live chassis.

When handling static sensitive components, an anti-static wrist strap is recommended. However, it should be constructed of high resistance materials with a high resistance path between you and the chassis (greater than 100K ohms). Never use metallic conductors as you would then become an excellent path to ground for line current or risk amputating your hand at the wrist when you accidentally contacted that 1000 A welder supply!

Don't attempt repair work when you are tired. Not only will you be more careless, but your primary diagnostic tool - deductive reasoning - will not be operating at full capacity.

Finally, never assume anything without checking it out for yourself! Don't take shortcuts!

Many people who mistakenly feel that ‘old technology’ is somehow more user-friendly, in some strange way automatically good - merely because it is old. Don’t be fooled! Approach old equipment with an open and alert mind and realise that a hot chassis, or a resistor line cord, or asbestos insulation, or selenium rectifiers require much more thought and consideration for safety.

Live chassis are indiscriminate in whom they kill and even if you are a thoughtful, careful kind of person, that doesn’t mean the last person who handled the set was.

Vintage radio and television receivers use 'live chassis' techniques, in which the chassis is connected directly to one side of the incoming mains supply. This means they can be lethal to carry out repair or servicing work on, unless the appropriate safety measures are in place.

Another thing about live-chassis sets - live spindles. We’ve touched on this already but it’s worth making the point once more. The shafts of switches and potentiometers fixed to the chassis may well be at chassis potential and thus live. The bakelite or wood cabinet is insulated but these shafts are not, and if someone lost the proper grub screw and replaced a knob using a cheesehead screw, the next person to grip that knob may get a dose of 250 volts. Originally these grub screws were sealed and embedded in wax but you cannot rely on subsequent tinkerers having the same high standards.

Even in more orthodox apparatus standards of insulation were not always as high as they are now. Soldered connections to HT and mains wiring should always have rubber or plastic sleeving but in times gone by this was often omitted (or it may since have perished). Beware too of kinked and frayed braiding on cloth-covered mains cords, particularly when the cord has a dropper conductor.

If you are not satisfied that you fully understand the risks involved in this sort of work, do not proceed any further. Instead seek advice and assistance from a competent technician or engineer.

Whenever you acquire a new treasure there's always a terrific temptation to try it out. With mains-driven equipment that means plugging it in and seeing if it works. Well don't, not until you have made some quick checks.

Before contemplating connecting any unknown receiver to the mains supply, spend a little time inspecting it for signs of missing or loose parts, blown fuses, overheating or even fire damage. Use a meter to check obvious points to ensure no short circuit exists (e.g. across the mains input). If you then decide to apply power keep clear but be observant since an elderly electrolytic might explode! This can be avoided if you can apply power gradually through a variac. Auto-transformers are handy for supplying reduced power to sets being repaired but they are not a substitute for a proper isolation transformer!

If you are working with electricity and your work area has a concrete floor, a rubber mat is essential, particularly during damp weather! Where possible try to arrange a neat working area away from water or central heating pipes. For safety try to arrange that this area is separate from the area occupied by your family. This is emphasised because inadvertently rushing to answer a telephone you might just leave a TV chassis connected to a supply and curious little fingers know nothing of the dangers of electricity - or, for that matter - the lethal vacuum encased within every picture tube!

Many younger enthusiasts may not be aware of the dangers of mishandling tubes, in particular the old round types found in early TVs. When handling these tubes eye protection should be worn and tubes must not be left lying around, they must be stored in boxes. The glass is surprising fragile and can implode without any provocation or warning. Bits of glass flying around at high speed can be deadly. The notes following are inspired by Malcolm Burrell again.

Picture tubes are perhaps one of the most hazardous items in any TV receiver. This is because most are of glass construction and contain a very high vacuum. If you measured the total area of glass in any picture tube then estimated the pressure of air upon it at 14.7lb. per square inch, you would discover that the total pressure upon the device could amount to several tons! Fracturing the glass suddenly would result in an extremely rapid implosion such that fragments of glass, metal and toxic chemicals would be scattered over a wide area, probably causing injury to anyone in close proximity. In modern workshops it is now a rule that protective goggles are worn when handling picture tubes.

The weakest point in most picture tubes is where the thin glass neck containing the electron gun is joined to the bowl. It is therefore essential that you refrain from handling the tube by its neck alone. Once a tube is removed from the receiver hold it vertically with the neck uppermost and one hand beneath the screen with the other steadying the device by the neck.With larger devices it is sometimes easier to grip the peripheral of the screen with both hands.

Until the advent of reinforced picture tubes, most were mounted in the cabinet or on the TV chassis by some form of metal band clamped around the face.Never support the weight of the tube by this band since it has been known for the tube to slide out! Some of the larger tubes are extremely heavy. It may, therefore, be easier to enlist assistance.

Before starting to remove a tube, first discharge the final anode connection to the chassis metalwork and preferably connect a shorting lead to this connection whilst you are working. It might be convenient to keep a spare piece of EHT cable with a crocodile clip at one end and a final anode connector at the other.

Exercise care when removing picture tubes from elderly equipment. You may find that the deflection coils have become stuck to the neck. It is extremely dangerous to use a screwdriver prise them away. Gently heating with a hairdryer or soaking in methylated spirit is safer.

Disposal of picture tubes also requires care. Unless rendered safe they should never be placed in dustbins or skips. Many engineers swipe the necks off tubes in cavalier fashion using a broom handle but this is not recommended. A safer method is to make a hole in the side of a stout carton, preferably one designed to hold a picture tube. The tube is placed in the carton and the neck broken using a broom handle. The carton should then be clearly labelled that it contains chemicals and broken glass!

Therefore people who believe they can conquer nature are clueless that the laws of nature are a precondition of their existence. Their weapon is a miserable idea.When man attempts to rebel against the iron logic of Nature, he comes into struggle with the principles to which he himself owes his existence as a man. And this attack must lead to his own doom.

Think for yourself. Otherwise you have to believe what other people tell you.

For most people thinking is a matter of fortune.A society based on individualism is an oxymoron.Freedom is at first the freedom to starve.A wise fool speaks, because he has something to say.A fool speaks, because he has to say something.A wise fool is silent, because there is nothing to say.A fool is silent, because he has nothing to say.

Resist or regretWork for what's good for our people

Help stem the dark tideStand tall or be beat downFight back or die

The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.

We now live in a nation where doctors destroy health, lawyers destroy justice, universities destroy knowledge, governments destroy freedom, the press destroys information, religion destroys morals and our banks destroy the economy.The globalist argument is that if only we erase distinctions, obliterate identities, put everyone on a level playing field, etc.. we can eliminate war and everyone can be so prosperous and efficient, such great cogs in a well-oiled global machine.There will be no more historical grievances because people will no longer even care, they'll have no connection to the past, no foolish pride in past accomplishments of people totally unrelated to them.A globalized culture, no borders, everyone a citizen of the world.Know this: I will never acquiesce to this corrupt, inhuman, Borg-like vision. The dangerous lunatics who push us towards their globalized "utopia" are my enemy. How exactly all this will play out, whether through wars, or whether we can thwart the globalist agenda peacefully (this is my hope of course) I don't know. But I do know that unless people are willing to fight and die, globalism will win out in the end.The actual crimes committed by the EU against the European peoples are directly in violation of the 1948 UN genocide convention, Article II: (c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; (d) Imposing measures intended to prevent births within the group; (e) Forcibly transferring children of the group to another group.* The man who does not exercise the first law of nature—that of self preservation — is not worthy of living and breathing the breath of life.

TELEVISION HISTORY IN BRIEF

Television history

At 1928 Baird transmits from London to New York, using his mechanical system.with 30 vertical lines. By 1930 it was clear that mechanical television systems could never produce the picture quality required for commercial success. For this reason mechanical system was rapidly succeeded by the electronic TV systems. The first all-electronic American systems in 1932 used only 120 scanning lines at 24 frames per second Since the mid-1930s picture repetition frequency (field rate or frame rate) has been the same as the mains frequency, either 50 or 60Hz according to the frequency used in each country. This is for two very good reasons. Studio lighting generally uses alternating current lamps and if these were not synchronised with the field frequency, an unwelcome strobe effect could appear on TV pictures. Secondly, in days gone by, the smoothing of power supply circuits in TV receivers was not as good as it is today and ripple superimposed on the DC could cause visual interference. If the picture was locked to the mains frequency, this interference would at least be static on the screen and thus less obtrusive.To determine what electronic system to use, the BBC sponsored trial broadcasts by two systems, one by Baird, with 240 lines, and one by EMI with 405 lines. Scheduled electronic television broadcasting began in England in 1936 using 405-line system (lasted until the 1980s in the UK). Germany made their forst TV broadcasts at 1936 olympics using 180-line TV system. Germany also made their TV broadcasts by the fall of 1937 using a 441-line system. Also fFrance tested TV (455 line system). RCA introduced electronic television to the U. S. at the 1939 World's Fair,and began regularly scheduled broadcasting at the same time (525 line system).In 1940 the USA established its 525-line standard. At year 1941 the 525-line standard, still in use today in USA, was adopted.Russia also produced TV sets before the war (240 and 343 line systems).World War Two interrupted the development of television. Immediately after World War Two production of TV sets started in the U.S-In USA there was TV broadcasts and few throusand receivers at 1945. In the early 1950s, two competing color TV systems emerged: CBS sequential color (used color wheel) and RCA dot sequential system. At 1953 color broadcasting officially arrives in the U.S. on Dec. 17, when FCC approves modified version of an RCA system.It calls this new RCA color system "NTSC" color. The first NTSC color TVs were on the marker at 1954.In Europe the TV broadcasts started to use experiment using 625 line system 1950s. This standard is used nowadays throughout Europe. France also tried 819 line system at the same time (this system was in use to 1980s). The rest of Europe opted for 625 lines, a system devised in 1946 by two German engineers, M??ller and Urtel (it appears that the Russians came up independently with a very similar system). The use of PAL color standard started at around 1967 and is still in use. The SECAM color system (used in France) testing started also at 1967. The TV broadcasting history has not ended. The newst thign is digital television. It is expected that terrestrial television will open up billion-dollar opportunities for those companies and organisations best prepared to embrace this new broadcasting era. At 1996 small digital satellite dishes hit the market. They become the biggest selling electronic item in history next to the VCR.

Using TV 24H

TV has something for everyone. Idiots, intellectuals, fans of all sorts. Some people are couch potatoes, watch anything just to sit there and be mindless. That's their problem. Children have always needed to be monitored by their parents. If people gotta a mind for it they could figure out the real news even without the internet and there has always been a library.

Is TV bad in and of itself? The researchers aren’t saying that. But we all know that watching television is a solitary, isolating occupation that keeps you sedentary. Sitting in front of the boob tube reduces the time you have available to exercise, interact with your family, read books, and be outdoors. This new research dovetails with other studies, which have linked excessive TV time to obesity and higher rates of cardiovascular disease.

watching too much television can jeopardize your whole family’s health.

This should be a wake-up call to all adults. Stay active. Go outside. Spend time with your spouse and your children with the television off. Read a book and do crossword puzzles to stimulate your imagination and your brain. Reduce your screen time as much as you can.

The National Cancer Institute researchers suggest that watching TV is a public health issue. The price we are paying for our technology-driven lives may be much higher than we previously realized !

DON'T WATCH TV AT ALL !!

The Propaganda TV Machine a.k.a. The Ministry of Truth delivers The Truth from The Government to the people.

At least, that's what they say. In fact, a Propaganda Machine is only employed by The Empire and used to brainwash people into Gullible Lemmings who believe that everything is all right when in fact, it isn't, and that the very people who could help them are their enemies.

Girl Looking TV.

Happy Times:

Do you remember when a telly looked like a real telly? When it was a piece of furniture that you lavished love on, even polished from time to time ?When it was a piece of somewhat at looking in to ?When it was a piece of Highest tech looking inside ? First, this site is a Digital free, HD free, flat panel, HDMI, China, Turks, Afrika free zone. All in all a wealth of vintage information at your finger tips, a one stop unique experience. So step on in, leave the modern throw-away world behind, travel back in time to a vintage world of repair and enjoy.This site has stirred memories about the watching TV's days on a CRT TUBE television......Childhood memories, your parents getting their first colour tv, a b/w or color portable, perhaps memories of renting or buying your first set remote featured, perhaps your days working in the trade, selling or repairing them....... If you enjoyed this site, found its content left you all misty eyed then just talk about it as it would be very welcome............like the time to recover and restore a set ................and happy reminiscing.

Digital TV in Brief.

Digital TV:

Digital television is a hot topic now.If you have looked at television sets at any of the big electronics retailers lately, you know that Digital TV, or DTV, is a BIG deal right now in the U.S. In Europe Digital TV is also a hot topic, because many countries have started terrestrial digital TV broadcasts and plan to end analogue broadcasts after some years (will take 5-10 years). Satellite TV broadcasts have also shifted very much to digital broadcasts.The main advantage if digital broadcasts are that it does not havethe picture quality problems of analogue TVs (it had it's own videoproblems caused by video compression), it allowes putting more TV channels to same medium (TV channel frequencies and satellites) and it allows new services (like HDTV and interactive multimedia). The digital brodcasts are generally designed to use such modulation that the digital data stream (typically around 20-30 Mbit/s) is modulated to the same bandwidth (around 6 MHz) as the analogue TV broadcasts. The used modulation vary between different media, which means thatdifferent modulation techniques are used in terrestrial transmissions, cable TV and satellite. Different modulations are used because of the different characteristics of those transmission medias. There is not on "digital TV", but several different variations of it in use.The basic technology of digital TV, known as MPEG 2 video compressionand MPEG 2 transmission stream format, is same around the world, butis is used somewhat differently in different standards used in differentcountries.

USA uses ACTS Digital Televisio Standard, which standardizes NTSC format transmissions, HDTV transmission, sound formats and data signal modulation in use. The ATSC MPEG-2 formats for DTV, including HDTV, uses 4:2:0 samling for video signal. The US system uses a fixed power and a fixed maximum bitrate, at which some bits are always transmitted. That rate is typically 19.3 Mb/sec.

Europe uses DVB (Digital Video Broadcasting) standard. This standardallows basically normal PAL resolution transmisssion (vasically HDTVcould be added later but is not yet standardized) with several audio formats, digital data rates and digital signal modulation. There are several different variations fo DVB standard for different media:

DVB-T for terrestrial broadcastsDVB-S for satelliteDVB-C for cable TV

Those different DVB versions varyon the data signal modulation methods, error correction and frequency bands used. DVB and option for some interactive extra services, but thestandardization of this is not ready here yet(there are fire different incompatible interactive servicessystems in use in different countries and by different broadcasters).

The process of transmitting digital TV signal is the following: Analog video/audio - digitisation - MPEG compression - Multiplexing ( youcan now call it digital) - Preparation for transmisson - modulation toanalog carrier.Reception process is the following: Demodulation of analogue carrier - Error correction - Demultiplexing - MPEG decompression - DA conversion to get analogue signal (unless you use digital display). The analoguie video signal that gets digitized can be practically from any video source, for example produced with old analogue video production equipment and distributed with a video tape. In high-end system the information is analogue only in the image sensor on the video camera, and from this on the signal gets digitally processed. In many real-life TV production systems the reality is something between those two extremes.

At least in Europe, the signal level requirements for DVB-T are well below the analog requirements, so the transmitter power is much less than on the analog side. In the NorDig recommendation the minimum received signal level for 64QAM, 7/8 code rate with a Rayleigh fading path and 8 dB receiver noise figure would be -64 dBm. With other code rates, modulations and fading mechanisms, the requirement is lower. Many receivers can perform much better at conditions where there is no fading (a quasi error free less than one uncorrected error/hour signal even at 27 dBuV (-82 dBm) with 64QAM and 8 MHz channel width). For analog signals, the recommended level is more than 1 mV (+60 dBuV, -49 dBm). While the ERP can be at least 10 dB lower than analog, the question of power consumption is more complicated, since COFDM with 64QAM carriers require a quite good linearity, which may affect the efficiency and hence power consumption.

Digital TV system in use in USA

The FCC mandate to change our broadcast standards from NTSC analog to ATSC digital broadcasting (DTV) is big bold move, requiring changes in everything from the way the studios shoot video, the format that's transmitted, to the equipment we use to receive and watch broadcastsDTV (digital TV) applies to digital broadcasts in general and to the U.S. ATSC standard in specific. The ATSC standard includes both standard-definition (SD) and high-definition (HD) digital formats. The notation H/DTV is often used to specifically refer to high-definition digital TV. The federal mandate grants the public airwaves to the broadcasters to transmit digital TV in exchange for return of the current analog NTSC spectrum, allowing for a transition period in the interim. At the end of this period scheduled for 2006, broadcasters must be fully converted to the 8VSB broadcast standard. Digital Television ("DTV") is a new broadcast technology that will transform television. The technology of DTV will allows TV broadcasts with movie-quality picture and CD- quality sound and a variety of other enhancements (for example data delivery). With digital television, broadcasters will be able to offer free television of higher resolution and better picture quality than now exists under the current mode of TV transmission. If broadcasters so choose, they can offer what has been called "high definition television" or HDTV, television with theater-quality pictures and CD-quality sound. . Alternatively, a broadcaster can offer several different TV programs at the same time, with pictures and sound quality better than is generally available today. HDTV (high-definition TV) encompasses both analog and digital televisions that have a 16:9 aspect ratio and approximately 5 times the resolution of standard TV (double vertical, double horizontal, wider aspect). High definition is generally defined as any video signal that is at least twice the quality of the current 480i (interlaced) analog broadcast signal. There are 18 approved formats for digital TV broadcasts, but only two (720p/1080i) are proper definition of the term HDTV. The advent of high definition has allowed monitors to read images differently, either in standard interlaced format or progressively. Sets that do not have any decoding capabilities but can display the high-resolution image is often labeled as "HD-Ready" a term that describes 80% or more of the Digital TVs on the market. HDTV displays support digital connections such as HDMI (DVI) and IEEE 1394/FireWire, although standardization is not finished. HDTV in the US is part of the ATSC DTV format. The resolution and frame rates of DTV in the US generally correspond to the ATSC recommendations for SD (640x480 and 704x480 at 24p, 30p, 60p, 60i) and HD (1280x720 at 24p, 20p, and 60p; 1920x1080 at 24p, 30p and 60i). In addition, a broadcaster will be able to simultaneously transmit a variety of other information through a data bitstream to both enhance its TV programs and to provide entirely new services. The technical specifications of USA DTV system is defined in ACTS Digital Television Standards.

Digital TV in Europe

Digital TV brodacasting in Europe is done according to DVB standards. DVB technology has become an integral part of global broadcasting, setting the global standard for satellite, cable and terrestrial transmissions and equipment. There are three versions of DVB in use: DVB-S, DVB-C and DVB-T.DVB-T is a flexible system allowing terrestrial broadcastersto choose from a variety of options to suit their various service environments. This allows the choice between fixed roof-top antenna, portableand even mobile reception of DVB-T services. Broadly speaking the trade-off in one of service bit-rate versus signal robustness.

DVB-T network is very flexible. Having many transmitters all on the same frequency is not a problem for the used COFDM based system. COFDM has been chosen and designed to minimise the effects of multipath in obstructed reception areas. In fact multipath signals can significantly improve the overall received signal with no adverse effects. These properties are particularly valuable for radio cameras and mobile links. DVB-T because of its unique design which allows single frequency networks (SFN). This means that many transmitters along the planned routes can transmit on the same frequency. It is also possible to use simple gap fillers that amplify and retransmit the signal. In-air digital TV broadcasts in Europe use DVB-T. 8 MHz of bandwidth may be used to provide a 24 Mbps digital transmission path using Coded Orthogonal Frequency Division Multiplexing (COFDM) modulation (theoretical maximum 31.67 Mbits for 8 MHz bandwidth). In cases where less bandwidth is available (6 or 7 MHz), the data rate is somewhat lower (around 20 Mbit/s).

DVB-C does the same function as DVB-T, but the modulation used in this system is optimized to operate well in cable TV networks. The modulation used in DVB-C is QAM. Systems from 16-QAM up to 256-QAM can be used, but the system centres on 64-QAM, in which an 8MHz channel can accommodate a physical payload of about 38 Mbit/s. Digital cable TV in Europe uses DVB-C. The DVB standard for the cable return path has been developed jointly with DAVIC, the Digital Audio Visual Council. The specification uses Quadrature Phase Shift Keying (QPSK) modulation in a 200kHz, 1MHz or 2MHz channel to provide a return path for interactive services (from the user to the service provider) of up to about 3Mbit/s. The path to the user may be either in-band (embedded in the MPEG-2 Transport Stream in the DVB-C channel) or out-of-band (on a separate 1 or 2MHz frequency band).

DVB-S is the satellite version of DVB. Satellite transmission has lead the way in delivering digital TV to viewers. Established in 1995, the satellite standard DVB-S is the oldest DVB standard, used on all six major continents. QPSK modulation system is used, with channel coding optimised to the error characteristics of the channel. A typical satellite channel has 36 MHz bandwidth, which may support transmission at up to 38 Mbps (assuming delivery to a 0.5m receiving antenna) using Quadrature Phase Shift Keying (QPSK) modulation. 16 bytes of Reed Solomon (RS) coding are added to each 188 byte transport packet to provide Forward Error Correction (FEC) using a RS(204,188,8) code. For the satellite transmission, the resultant bit stream is then interleaved and convolutional coding is applied.

The core of the DVB digital data stream isthe standard MPEG-2 "data container",which holds the broadcast and service information.This flexible "carry-all" can containanything that can be digitised, includingmultimedia data. The MPEG-2 standards define how to format the various component parts of a multimedia programme (which may consist of: MPEG-2 compressed video, compressed audio, control data and/or user data). It also defines how these components are combined into a single synchronous transmission bit stream. The process of combining the steams is known as multiplexing. The multiplexed stream may be transmitted over a variety of links, standards / products.Each MPEG-2 MPTS multiplex carries a number of streams which in combination deliver the required services. A typical data rate of such multiplex is around 24 Mbps for terrestrial brodcasts.

European DVB systems currently transmit only standard definition TV signals and set top boxes also handle only normal TV resolution. It would be possible to transmit HDTV signals on DVB data stream, but those broadcasts have not yet started in any wide scale. There is one satellite broadcater that broadcasts HDTV DVB signals in Europe (some cable TV operators carry that signal on their cable).

Many DVB-T integrated TV sets, and some set top boxes, in the Europe come with a Common Interface slot - which is pretty much the same form-factor as a PC Card (aka PCMCIA) used in PC laptops. This CI slot accepts a Conditional Access Module, in the same way that DVB-S receivers do, which implements at least one (some can do more than one) decryption algorithm. This CAM may also, itself, have a smart card slot to accept a consumer subscription card to authorise decryption - you plug your smartcard into your CAM and your CAM into the CI slot in your receiver/IDTV. Some DVB receivers have an integrated CAM (in the case of some receivers this is implemented purely in software, with no extra hardware required) rather than a CI slot to plug in a 3rd party device. With these type of receivers you just plug in the smart card and don't have to worry about CI slots and buying CAMs. So there is an interface standard for DVB - but different broadcasters can chose different encryption schemes, requiring different CAMs for decryption.

DVB Standards and related documents are published by the European Telecommunications Standards Institute (ETSI). These include a large number of standards and technical notes to complement the MPEG-2 standards defined by the ISO.

There are few different standard how interactive TV functionaly is implemented in DVB-systems in use in differenct countries. DVB-MHP is one gaining some acceptance. Multimedia Home Platform (MHP) is the open middleware system designed by the DVB Project (www.dvb.org).